The motto – and accompanying clothes and DVDs – have infuriated law enforcement officials, who see it as “witness intimidation on a T-shirt.” But in “Snitch,” Brown argues that “Stop Snitching” is less about letting the bad guys go free than it is a complaint against cooperating witnesses who lie to get lighter sentences.

It all goes back to anti-crime legislation from the 1980s, which set up mandatory minimums and increased the penalties for small-fry pushers caught with minuscule amounts of crack. Suddenly, defendants were faced with longer, ironclad sentences.

The only out was Section 5K.1 of the U.S. sentencing guidelines. If defendants gave “substantial assistance” to prosecutors, they had a shot at a reduced sentence. Desperate for a downward departure, Brown writes, some cooperating witnesses are lying to earn a break.

The end result is people going to prison for crimes they didn’t commit. In 46 percent of wrongful death penalty convictions, an “incentivized” witness provided bad information, according to the Northwestern University Law School’s Center on Wrongful Convictions.

Not only are cooperating witnesses putting innocent people in prison, the practice is also letting hardened criminals out too soon, Brown says.

He cites the case of cooperating witness Ricky Javon Gray, who was later convicted of murdering Bryan and Kathryn Harvey and their young daughters, Ruby and Stella, during a brutal 2006 home invasion in Richmond, Va. If Grayhadn’t been given a lighter sentence, Brown writes, Gray would have been in prison and the Harvey family would still be alive.

Nobody counts how often prosecutors make cooperation deals, though Brown quotes legal experts saying it’s widespread. Some – like the Irv Gotti and Tupac Shakur cases – are widely known, though he also tells the stories of small-time dealers who are forced to help DEA agents bring in other “retailers,” even though the operations make only a small dent in the drug trade.

Brown makes a persuasive argument that cooperating witnesses who lie are a major problem, and he digs deep into individual cases to show how regular people are being cheated of justice. “Snitch” is both a policy book and a solid true-crime read.

Brown writes less about witness intimidation. Police say they have a hard time closing cases because witnesses fear they’ll be killed if they testify.

“Snitch” acknowledges the problem, but notes that authorities aren’t completely blameless, either. Too many departments don’t protect their witnesses, Brown writes. Or they bungle the investigation, causing witnesses to lose confidence and back out.

“It was never made to intimidate people from calling the cops,” Rodney Bethea, who produced the original “Stop Snitching” in Baltimore, tells Brown, “and it was never directed at what they call ‘civilians.’ If your grandmother calls the cops on people who are selling drugs on her block, she’s supposed to do that because she’s not living this lifestyle.”

It sounds like a reasonable explanation. It’s also one that never seems to end up on a T-shirt.